UPSTREAM: extensions: libxt_bpf: fix missing __NR_bpf declaration

This include is needed to compile the bpf_obj_get function properly,
as it brings in the __NR_bpf declaration.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Chenbo Feng <fengc@google.com>

Clean cherry-pick, no conflict.
(cherry picked from commit 895ce096f857ddc85d22144ba84c78ac762e995d)

Bug: 72111305
Test: With BPF_H defined
      iptables -t raw -I bw_raw_PREROUTING -m bpf --object-pinned /sys/fs/bpf/xtbpf_prog
      should not return error about bpf header not find.

Change-Id: Ia1387e61c8415a9ae6d3532830fbf62414740855
(cherry picked from aosp commit ff75e02e65ef4c7b457e245b9d6c3df82aff1798)
1 file changed